The CAN bus wires are two twisted pairs.
The CAN bus is a differential bus. The bus value is determined by the potential difference between the two wires of the twisted pair, and the bus value has both explicit and implicit states.
The high performance and reliability of CAN has been recognized and is widely used in industrial automation, ships, medical devices, industrial equipment, and more. Fieldbus is one of the hotspots of technological development in the field of automation today, and is known as the computer LAN in the field of automation. Its emergence provides strong technical support for distributed control systems to realize real-time, reliable data communication between nodes.
Expanded Information
One of the most important features of the CAN protocol is that it abolishes the traditional station address encoding and replaces it with encoding of communication data blocks. The advantages of using this method allow the number of nodes within the network to be theoretically unlimited. The identifier of the data block can consist of either an 11-bit or a 29-bit binary number, so that 2 or more different data blocks can be defined. This per-block encoding
also allows different nodes to receive the same data at the same time, which is very useful in a distributed control system. The data segment length is up to 8 bytes, which meets the general requirements for control commands, operating status and test data in usual industrial areas. At the same time, 8 bytes will not take up too much bus time, thus ensuring real-time communication.
The CAN protocol uses CRC checking and provides corresponding error handling functions to ensure the reliability of data communication.
CAN's excellent characteristics, high reliability and unique design are particularly suitable for interconnecting industrial process monitoring equipment, and therefore, it is getting more and more attention from the industrial world, and has been recognized as one of the most promising field buses.
Baidu Encyclopedia - CAN Bus